1 /*
2 * Philips UCB1400 touchscreen driver
3 *
4 * Author: Nicolas Pitre
5 * Created: September 25, 2006
6 * Copyright: MontaVista Software, Inc.
7 *
8 * Spliting done by: Marek Vasut <marek.vasut@gmail.com>
9 * If something doesn't work and it worked before spliting, e-mail me,
10 * dont bother Nicolas please ;-)
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 *
16 * This code is heavily based on ucb1x00-*.c copyrighted by Russell King
17 * covering the UCB1100, UCB1200 and UCB1300.. Support for the UCB1400 has
18 * been made separate from ucb1x00-core/ucb1x00-ts on Russell's request.
19 */
20
21 #include <linux/module.h>
22 #include <linux/delay.h>
23 #include <linux/sched.h>
24 #include <linux/wait.h>
25 #include <linux/input.h>
26 #include <linux/device.h>
27 #include <linux/interrupt.h>
28 #include <linux/ucb1400.h>
29
30 #define UCB1400_TS_POLL_PERIOD 10 /* ms */
31
32 static bool adcsync;
33 static int ts_delay = 55; /* us */
34 static int ts_delay_pressure; /* us */
35
36 /* Switch to interrupt mode. */
ucb1400_ts_mode_int(struct ucb1400_ts * ucb)37 static void ucb1400_ts_mode_int(struct ucb1400_ts *ucb)
38 {
39 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
40 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
41 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
42 UCB_TS_CR_MODE_INT);
43 }
44
45 /*
46 * Switch to pressure mode, and read pressure. We don't need to wait
47 * here, since both plates are being driven.
48 */
ucb1400_ts_read_pressure(struct ucb1400_ts * ucb)49 static unsigned int ucb1400_ts_read_pressure(struct ucb1400_ts *ucb)
50 {
51 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
52 UCB_TS_CR_TSMX_POW | UCB_TS_CR_TSPX_POW |
53 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_GND |
54 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
55
56 udelay(ts_delay_pressure);
57
58 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
59 }
60
61 /*
62 * Switch to X position mode and measure Y plate. We switch the plate
63 * configuration in pressure mode, then switch to position mode. This
64 * gives a faster response time. Even so, we need to wait about 55us
65 * for things to stabilise.
66 */
ucb1400_ts_read_xpos(struct ucb1400_ts * ucb)67 static unsigned int ucb1400_ts_read_xpos(struct ucb1400_ts *ucb)
68 {
69 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
70 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
71 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
72 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
73 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
74 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
75 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
76 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
77 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
78
79 udelay(ts_delay);
80
81 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPY, adcsync);
82 }
83
84 /*
85 * Switch to Y position mode and measure X plate. We switch the plate
86 * configuration in pressure mode, then switch to position mode. This
87 * gives a faster response time. Even so, we need to wait about 55us
88 * for things to stabilise.
89 */
ucb1400_ts_read_ypos(struct ucb1400_ts * ucb)90 static int ucb1400_ts_read_ypos(struct ucb1400_ts *ucb)
91 {
92 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
93 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
94 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
95 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
96 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
97 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
98 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
99 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
100 UCB_TS_CR_MODE_POS | UCB_TS_CR_BIAS_ENA);
101
102 udelay(ts_delay);
103
104 return ucb1400_adc_read(ucb->ac97, UCB_ADC_INP_TSPX, adcsync);
105 }
106
107 /*
108 * Switch to X plate resistance mode. Set MX to ground, PX to
109 * supply. Measure current.
110 */
ucb1400_ts_read_xres(struct ucb1400_ts * ucb)111 static unsigned int ucb1400_ts_read_xres(struct ucb1400_ts *ucb)
112 {
113 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
114 UCB_TS_CR_TSMX_GND | UCB_TS_CR_TSPX_POW |
115 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
116 return ucb1400_adc_read(ucb->ac97, 0, adcsync);
117 }
118
119 /*
120 * Switch to Y plate resistance mode. Set MY to ground, PY to
121 * supply. Measure current.
122 */
ucb1400_ts_read_yres(struct ucb1400_ts * ucb)123 static unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
124 {
125 ucb1400_reg_write(ucb->ac97, UCB_TS_CR,
126 UCB_TS_CR_TSMY_GND | UCB_TS_CR_TSPY_POW |
127 UCB_TS_CR_MODE_PRES | UCB_TS_CR_BIAS_ENA);
128 return ucb1400_adc_read(ucb->ac97, 0, adcsync);
129 }
130
ucb1400_ts_pen_up(struct ucb1400_ts * ucb)131 static int ucb1400_ts_pen_up(struct ucb1400_ts *ucb)
132 {
133 unsigned short val = ucb1400_reg_read(ucb->ac97, UCB_TS_CR);
134
135 return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
136 }
137
ucb1400_ts_irq_enable(struct ucb1400_ts * ucb)138 static void ucb1400_ts_irq_enable(struct ucb1400_ts *ucb)
139 {
140 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, UCB_IE_TSPX);
141 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
142 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_TSPX);
143 }
144
ucb1400_ts_irq_disable(struct ucb1400_ts * ucb)145 static void ucb1400_ts_irq_disable(struct ucb1400_ts *ucb)
146 {
147 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
148 }
149
ucb1400_ts_report_event(struct input_dev * idev,u16 pressure,u16 x,u16 y)150 static void ucb1400_ts_report_event(struct input_dev *idev, u16 pressure, u16 x, u16 y)
151 {
152 input_report_abs(idev, ABS_X, x);
153 input_report_abs(idev, ABS_Y, y);
154 input_report_abs(idev, ABS_PRESSURE, pressure);
155 input_report_key(idev, BTN_TOUCH, 1);
156 input_sync(idev);
157 }
158
ucb1400_ts_event_release(struct input_dev * idev)159 static void ucb1400_ts_event_release(struct input_dev *idev)
160 {
161 input_report_abs(idev, ABS_PRESSURE, 0);
162 input_report_key(idev, BTN_TOUCH, 0);
163 input_sync(idev);
164 }
165
ucb1400_clear_pending_irq(struct ucb1400_ts * ucb)166 static void ucb1400_clear_pending_irq(struct ucb1400_ts *ucb)
167 {
168 unsigned int isr;
169
170 isr = ucb1400_reg_read(ucb->ac97, UCB_IE_STATUS);
171 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, isr);
172 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
173
174 if (isr & UCB_IE_TSPX)
175 ucb1400_ts_irq_disable(ucb);
176 else
177 dev_dbg(&ucb->ts_idev->dev,
178 "ucb1400: unexpected IE_STATUS = %#x\n", isr);
179 }
180
181 /*
182 * A restriction with interrupts exists when using the ucb1400, as
183 * the codec read/write routines may sleep while waiting for codec
184 * access completion and uses semaphores for access control to the
185 * AC97 bus. Therefore the driver is forced to use threaded interrupt
186 * handler.
187 */
ucb1400_irq(int irqnr,void * devid)188 static irqreturn_t ucb1400_irq(int irqnr, void *devid)
189 {
190 struct ucb1400_ts *ucb = devid;
191 unsigned int x, y, p;
192 bool penup;
193
194 if (unlikely(irqnr != ucb->irq))
195 return IRQ_NONE;
196
197 ucb1400_clear_pending_irq(ucb);
198
199 /* Start with a small delay before checking pendown state */
200 msleep(UCB1400_TS_POLL_PERIOD);
201
202 while (!ucb->stopped && !(penup = ucb1400_ts_pen_up(ucb))) {
203
204 ucb1400_adc_enable(ucb->ac97);
205 x = ucb1400_ts_read_xpos(ucb);
206 y = ucb1400_ts_read_ypos(ucb);
207 p = ucb1400_ts_read_pressure(ucb);
208 ucb1400_adc_disable(ucb->ac97);
209
210 ucb1400_ts_report_event(ucb->ts_idev, p, x, y);
211
212 wait_event_timeout(ucb->ts_wait, ucb->stopped,
213 msecs_to_jiffies(UCB1400_TS_POLL_PERIOD));
214 }
215
216 ucb1400_ts_event_release(ucb->ts_idev);
217
218 if (!ucb->stopped) {
219 /* Switch back to interrupt mode. */
220 ucb1400_ts_mode_int(ucb);
221 ucb1400_ts_irq_enable(ucb);
222 }
223
224 return IRQ_HANDLED;
225 }
226
ucb1400_ts_stop(struct ucb1400_ts * ucb)227 static void ucb1400_ts_stop(struct ucb1400_ts *ucb)
228 {
229 /* Signal IRQ thread to stop polling and disable the handler. */
230 ucb->stopped = true;
231 mb();
232 wake_up(&ucb->ts_wait);
233 disable_irq(ucb->irq);
234
235 ucb1400_ts_irq_disable(ucb);
236 ucb1400_reg_write(ucb->ac97, UCB_TS_CR, 0);
237 }
238
239 /* Must be called with ts->lock held */
ucb1400_ts_start(struct ucb1400_ts * ucb)240 static void ucb1400_ts_start(struct ucb1400_ts *ucb)
241 {
242 /* Tell IRQ thread that it may poll the device. */
243 ucb->stopped = false;
244 mb();
245
246 ucb1400_ts_mode_int(ucb);
247 ucb1400_ts_irq_enable(ucb);
248
249 enable_irq(ucb->irq);
250 }
251
ucb1400_ts_open(struct input_dev * idev)252 static int ucb1400_ts_open(struct input_dev *idev)
253 {
254 struct ucb1400_ts *ucb = input_get_drvdata(idev);
255
256 ucb1400_ts_start(ucb);
257
258 return 0;
259 }
260
ucb1400_ts_close(struct input_dev * idev)261 static void ucb1400_ts_close(struct input_dev *idev)
262 {
263 struct ucb1400_ts *ucb = input_get_drvdata(idev);
264
265 ucb1400_ts_stop(ucb);
266 }
267
268 #ifndef NO_IRQ
269 #define NO_IRQ 0
270 #endif
271
272 /*
273 * Try to probe our interrupt, rather than relying on lots of
274 * hard-coded machine dependencies.
275 */
ucb1400_ts_detect_irq(struct ucb1400_ts * ucb,struct platform_device * pdev)276 static int ucb1400_ts_detect_irq(struct ucb1400_ts *ucb,
277 struct platform_device *pdev)
278 {
279 unsigned long mask, timeout;
280
281 mask = probe_irq_on();
282
283 /* Enable the ADC interrupt. */
284 ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, UCB_IE_ADC);
285 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, UCB_IE_ADC);
286 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
287 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
288
289 /* Cause an ADC interrupt. */
290 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA);
291 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, UCB_ADC_ENA | UCB_ADC_START);
292
293 /* Wait for the conversion to complete. */
294 timeout = jiffies + HZ/2;
295 while (!(ucb1400_reg_read(ucb->ac97, UCB_ADC_DATA) &
296 UCB_ADC_DAT_VALID)) {
297 cpu_relax();
298 if (time_after(jiffies, timeout)) {
299 dev_err(&pdev->dev, "timed out in IRQ probe\n");
300 probe_irq_off(mask);
301 return -ENODEV;
302 }
303 }
304 ucb1400_reg_write(ucb->ac97, UCB_ADC_CR, 0);
305
306 /* Disable and clear interrupt. */
307 ucb1400_reg_write(ucb->ac97, UCB_IE_RIS, 0);
308 ucb1400_reg_write(ucb->ac97, UCB_IE_FAL, 0);
309 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0xffff);
310 ucb1400_reg_write(ucb->ac97, UCB_IE_CLEAR, 0);
311
312 /* Read triggered interrupt. */
313 ucb->irq = probe_irq_off(mask);
314 if (ucb->irq < 0 || ucb->irq == NO_IRQ)
315 return -ENODEV;
316
317 return 0;
318 }
319
ucb1400_ts_probe(struct platform_device * pdev)320 static int ucb1400_ts_probe(struct platform_device *pdev)
321 {
322 struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
323 int error, x_res, y_res;
324 u16 fcsr;
325
326 ucb->ts_idev = input_allocate_device();
327 if (!ucb->ts_idev) {
328 error = -ENOMEM;
329 goto err;
330 }
331
332 /* Only in case the IRQ line wasn't supplied, try detecting it */
333 if (ucb->irq < 0) {
334 error = ucb1400_ts_detect_irq(ucb, pdev);
335 if (error) {
336 dev_err(&pdev->dev, "IRQ probe failed\n");
337 goto err_free_devs;
338 }
339 }
340 dev_dbg(&pdev->dev, "found IRQ %d\n", ucb->irq);
341
342 init_waitqueue_head(&ucb->ts_wait);
343
344 input_set_drvdata(ucb->ts_idev, ucb);
345
346 ucb->ts_idev->dev.parent = &pdev->dev;
347 ucb->ts_idev->name = "UCB1400 touchscreen interface";
348 ucb->ts_idev->id.vendor = ucb1400_reg_read(ucb->ac97,
349 AC97_VENDOR_ID1);
350 ucb->ts_idev->id.product = ucb->id;
351 ucb->ts_idev->open = ucb1400_ts_open;
352 ucb->ts_idev->close = ucb1400_ts_close;
353 ucb->ts_idev->evbit[0] = BIT_MASK(EV_ABS) | BIT_MASK(EV_KEY);
354 ucb->ts_idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
355
356 /*
357 * Enable ADC filter to prevent horrible jitter on Colibri.
358 * This also further reduces jitter on boards where ADCSYNC
359 * pin is connected.
360 */
361 fcsr = ucb1400_reg_read(ucb->ac97, UCB_FCSR);
362 ucb1400_reg_write(ucb->ac97, UCB_FCSR, fcsr | UCB_FCSR_AVE);
363
364 ucb1400_adc_enable(ucb->ac97);
365 x_res = ucb1400_ts_read_xres(ucb);
366 y_res = ucb1400_ts_read_yres(ucb);
367 ucb1400_adc_disable(ucb->ac97);
368 dev_dbg(&pdev->dev, "x/y = %d/%d\n", x_res, y_res);
369
370 input_set_abs_params(ucb->ts_idev, ABS_X, 0, x_res, 0, 0);
371 input_set_abs_params(ucb->ts_idev, ABS_Y, 0, y_res, 0, 0);
372 input_set_abs_params(ucb->ts_idev, ABS_PRESSURE, 0, 0, 0, 0);
373
374 ucb1400_ts_stop(ucb);
375
376 error = request_threaded_irq(ucb->irq, NULL, ucb1400_irq,
377 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
378 "UCB1400", ucb);
379 if (error) {
380 dev_err(&pdev->dev,
381 "unable to grab irq%d: %d\n", ucb->irq, error);
382 goto err_free_devs;
383 }
384
385 error = input_register_device(ucb->ts_idev);
386 if (error)
387 goto err_free_irq;
388
389 return 0;
390
391 err_free_irq:
392 free_irq(ucb->irq, ucb);
393 err_free_devs:
394 input_free_device(ucb->ts_idev);
395 err:
396 return error;
397 }
398
ucb1400_ts_remove(struct platform_device * pdev)399 static int ucb1400_ts_remove(struct platform_device *pdev)
400 {
401 struct ucb1400_ts *ucb = dev_get_platdata(&pdev->dev);
402
403 free_irq(ucb->irq, ucb);
404 input_unregister_device(ucb->ts_idev);
405
406 return 0;
407 }
408
409 #ifdef CONFIG_PM_SLEEP
ucb1400_ts_suspend(struct device * dev)410 static int ucb1400_ts_suspend(struct device *dev)
411 {
412 struct ucb1400_ts *ucb = dev_get_platdata(dev);
413 struct input_dev *idev = ucb->ts_idev;
414
415 mutex_lock(&idev->mutex);
416
417 if (idev->users)
418 ucb1400_ts_start(ucb);
419
420 mutex_unlock(&idev->mutex);
421 return 0;
422 }
423
ucb1400_ts_resume(struct device * dev)424 static int ucb1400_ts_resume(struct device *dev)
425 {
426 struct ucb1400_ts *ucb = dev_get_platdata(dev);
427 struct input_dev *idev = ucb->ts_idev;
428
429 mutex_lock(&idev->mutex);
430
431 if (idev->users)
432 ucb1400_ts_stop(ucb);
433
434 mutex_unlock(&idev->mutex);
435 return 0;
436 }
437 #endif
438
439 static SIMPLE_DEV_PM_OPS(ucb1400_ts_pm_ops,
440 ucb1400_ts_suspend, ucb1400_ts_resume);
441
442 static struct platform_driver ucb1400_ts_driver = {
443 .probe = ucb1400_ts_probe,
444 .remove = ucb1400_ts_remove,
445 .driver = {
446 .name = "ucb1400_ts",
447 .owner = THIS_MODULE,
448 .pm = &ucb1400_ts_pm_ops,
449 },
450 };
451 module_platform_driver(ucb1400_ts_driver);
452
453 module_param(adcsync, bool, 0444);
454 MODULE_PARM_DESC(adcsync, "Synchronize touch readings with ADCSYNC pin.");
455
456 module_param(ts_delay, int, 0444);
457 MODULE_PARM_DESC(ts_delay, "Delay between panel setup and"
458 " position read. Default = 55us.");
459
460 module_param(ts_delay_pressure, int, 0444);
461 MODULE_PARM_DESC(ts_delay_pressure,
462 "delay between panel setup and pressure read."
463 " Default = 0us.");
464
465 MODULE_DESCRIPTION("Philips UCB1400 touchscreen driver");
466 MODULE_LICENSE("GPL");
467